diff options
author | Thomas Gleixner <tglx@linutronix.de> | 2011-05-14 12:06:36 +0200 |
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committer | Thomas Gleixner <tglx@linutronix.de> | 2011-05-14 12:06:36 +0200 |
commit | a18f22a968de17b29f2310cdb7ba69163e65ec15 (patch) | |
tree | a7d56d88fad5e444d7661484109758a2f436129e /arch/unicore32/kernel/stacktrace.c | |
parent | a1c57e0fec53defe745e64417eacdbd3618c3e66 (diff) | |
parent | 798778b8653f64b7b2162ac70eca10367cff6ce8 (diff) |
Merge branch 'consolidate-clksrc-i8253' of master.kernel.org:~rmk/linux-2.6-arm into timers/clocksource
Conflicts:
arch/ia64/kernel/cyclone.c
arch/mips/kernel/i8253.c
arch/x86/kernel/i8253.c
Reason: Resolve conflicts so further cleanups do not conflict further
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'arch/unicore32/kernel/stacktrace.c')
-rw-r--r-- | arch/unicore32/kernel/stacktrace.c | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/arch/unicore32/kernel/stacktrace.c b/arch/unicore32/kernel/stacktrace.c new file mode 100644 index 000000000000..b34030bdabe3 --- /dev/null +++ b/arch/unicore32/kernel/stacktrace.c @@ -0,0 +1,131 @@ +/* + * linux/arch/unicore32/kernel/stacktrace.c + * + * Code specific to PKUnity SoC and UniCore ISA + * + * Copyright (C) 2001-2010 GUAN Xue-tao + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ +#include <linux/module.h> +#include <linux/sched.h> +#include <linux/stacktrace.h> + +#include <asm/stacktrace.h> + +#if defined(CONFIG_FRAME_POINTER) +/* + * Unwind the current stack frame and store the new register values in the + * structure passed as argument. Unwinding is equivalent to a function return, + * hence the new PC value rather than LR should be used for backtrace. + * + * With framepointer enabled, a simple function prologue looks like this: + * mov ip, sp + * stmdb sp!, {fp, ip, lr, pc} + * sub fp, ip, #4 + * + * A simple function epilogue looks like this: + * ldm sp, {fp, sp, pc} + * + * Note that with framepointer enabled, even the leaf functions have the same + * prologue and epilogue, therefore we can ignore the LR value in this case. + */ +int notrace unwind_frame(struct stackframe *frame) +{ + unsigned long high, low; + unsigned long fp = frame->fp; + + /* only go to a higher address on the stack */ + low = frame->sp; + high = ALIGN(low, THREAD_SIZE); + + /* check current frame pointer is within bounds */ + if (fp < (low + 12) || fp + 4 >= high) + return -EINVAL; + + /* restore the registers from the stack frame */ + frame->fp = *(unsigned long *)(fp - 12); + frame->sp = *(unsigned long *)(fp - 8); + frame->pc = *(unsigned long *)(fp - 4); + + return 0; +} +#endif + +void notrace walk_stackframe(struct stackframe *frame, + int (*fn)(struct stackframe *, void *), void *data) +{ + while (1) { + int ret; + + if (fn(frame, data)) + break; + ret = unwind_frame(frame); + if (ret < 0) + break; + } +} +EXPORT_SYMBOL(walk_stackframe); + +#ifdef CONFIG_STACKTRACE +struct stack_trace_data { + struct stack_trace *trace; + unsigned int no_sched_functions; + unsigned int skip; +}; + +static int save_trace(struct stackframe *frame, void *d) +{ + struct stack_trace_data *data = d; + struct stack_trace *trace = data->trace; + unsigned long addr = frame->pc; + + if (data->no_sched_functions && in_sched_functions(addr)) + return 0; + if (data->skip) { + data->skip--; + return 0; + } + + trace->entries[trace->nr_entries++] = addr; + + return trace->nr_entries >= trace->max_entries; +} + +void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) +{ + struct stack_trace_data data; + struct stackframe frame; + + data.trace = trace; + data.skip = trace->skip; + + if (tsk != current) { + data.no_sched_functions = 1; + frame.fp = thread_saved_fp(tsk); + frame.sp = thread_saved_sp(tsk); + frame.lr = 0; /* recovered from the stack */ + frame.pc = thread_saved_pc(tsk); + } else { + register unsigned long current_sp asm("sp"); + + data.no_sched_functions = 0; + frame.fp = (unsigned long)__builtin_frame_address(0); + frame.sp = current_sp; + frame.lr = (unsigned long)__builtin_return_address(0); + frame.pc = (unsigned long)save_stack_trace_tsk; + } + + walk_stackframe(&frame, save_trace, &data); + if (trace->nr_entries < trace->max_entries) + trace->entries[trace->nr_entries++] = ULONG_MAX; +} + +void save_stack_trace(struct stack_trace *trace) +{ + save_stack_trace_tsk(current, trace); +} +EXPORT_SYMBOL_GPL(save_stack_trace); +#endif |